
So consider having two tables with a many to many relationship. I would like to create a collection of Students with an added column 'teacher names'. this column would have a comma separated list of teacher names related to that student. I have tried a few ways to go round this using a lookup inside a concatenate while creating the collection but does not seem to work
This blog post by @WarrenBelz may help?
https://www.practicalpowerapps.com/data/many-to-many-filters/